Effect of Depolymerized Pyrodextrin on Human Intestinal Flora

抄録

A new depolymerized pyrodextrin (DPD) was produced by hydrolyzing pyrodextrin, a material of indigestible dextrin, with hydrochloric acid and then heating.The effects of this substance was examined in an in vitro fermentation test of human intestinal bacteria and in a continuous ingestion test on healthy subjects. The fermentability of the indigestible portion of DPD by 106 bacterial strains from the human intestine was examined in vitro. The indigestible portion of DPD was fermented by most strains of genus Bifidobacterium, apart from B. bifidum and B. animalis. The indigestible portion of DPD-II (dextrose equivalent (DE); 33.0), which resulted from advanced acid hydrolysis, was fermented more than the indigestible portion of DPD-I (DE; 23.6). The indigestible portion of these DPDs was not fermented by Clostridium peringens, C. difficile, Escherichia coli, and staphylococci. After 14 days of daily ingestion of 10 g of DPD-II by seven healthy males, the number of fecal bifidobacteria had increased significantly in comparison with the level before ingestion. However, the number of bacteroides, the predominant bacteria in the human intestine, did not change. These results suggest that DPD, a depolymerized pyrodextrin that was, hydrolyzed without much change in the branched binding, may help to increase the number of bifidobacteria in the human intestinal flora.